If a = and b = -1 what is the value of ab -b^2

Kapil needed to buy a long wooden beam. he went to two sawmills that each charge an initial fee plus an additional fee for each meter of wood. the following equation gives the price (in dollars) of a wooden beam from the first sawmill as a function of its length (in meters). p = 5+20xp=5+20x

Determine which expressions represent real numbers and which expressions represent complex number. asaaap! plis!

Write an equation of the line that passes through 9,2 and is parallel to the line y=5/3x+9